Re: Official Pokemon Discussion Thread!
In the gen II games, the best Pokemon to catch the Legendary Dogs - and Pokemon in general - is a Gengar. It's very fast, learns Mean Look to prevent them from running, and can put Pokemon to sleep with Hypnosis. It's perfect to catch Entei, Raikou and Suicune with, because they'll try to run, but if you're Gengar is well trained you can easily outspeed them at a lower level and Mean Look them to prevent them from Running. I have had a Gengar a few times leveled in it's 30's outspeed the level 40 Legendary Dogs, then trapping them, putting them to sleep, wearing them down, and catching them. On my last few files I have a Scyther handy with me to use False Swipe when they're sleep to get them down to 1HP making them MUCH easier to catch.